The scavanger used to be fitted to the expiratory port on the 3100B circuit and was then attached, I believe, to the vacuum point in the wall. The scavenger itself was originally designed for the removal of Nitric Oxide from the exhaust gas. It is not perfect as it does not form a air tight seal around the expiratory port, but it is certainly better then nothing.
The newer circuit does have a anti-bac filter in the expiratory limb but I think it needs changing every 24 hours, which pretty much renders it useless as you would need to change the circuit, not the filter, every 24 hours and then you would need to start recruiting the lung again.
If only someone else sold a oscillator with a proper filter which would be suitable for this
Mark
